Aha! was flat facts

[Sarah Fox]

Hi William,

I see and understand your point, but the micro-slippage I'm talking about is
NOT with respect to the entire pin at one time.  I'm talking about
microslippages of small fractions of the mating area between the pin and
block that accumulate over time.

Dean, I also understand your point about static vs. dynamic friction, but if
we're only talking about small portions of the entire pin-to-block contact
area, then indeed we can be talking about "microjumps."

Y'all have my curiosity piqued.  I'll try this experiment with a little
Hamilton that has a decent pinblock but isn't very well humidity controlled
and isn't tuned on a very frequent basis.  Perhaps y'all can help me to
establish the experimental parameters?  What minimum and maximum tuning pin
torques??? I'll select a few pins to meet with those parameters and monitor
them.  I'll measure the angle closest to horizontal that I can hang my
tuning hammer from these pins, as measured with an engineer's compass/level.
Or perhaps I'll use some sort of spring-loaded clamp, as the measurements
might be more repeatable.  I won't be able to get to it for a few weeks, but
I think I'll definitely do it.  Sounds interesting.

Weird that this hasn't been done before!!

Peace,
Sarah


----- Original Message ----- 
From: "William R. Monroe" <pianotech@a440piano.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Monday, March 28, 2005 9:16 AM
Subject: Re: Aha! was flat facts


> Not sure if I made myself clear on that last bit, "What's more, this
assumes
> that friction is constant, whatever the pins position in the hole."  What
I
> mean is, if static friction has been overcome and the pin started to move,
> is it not possible that after the tiniest movement, the pin encounters a
> structural "something" in the block which results in an increase in
friction
> in that position, stopping the pin's movement?
>
> Respectfully,
> William R. Monroe
>
> ----- Original Message ----- 
> From: "William R. Monroe" <pianotech@a440piano.net>
> To: "Pianotech" <pianotech@ptg.org>
> Sent: Monday, March 28, 2005 8:13 AM
> Subject: Re: Aha! was flat facts
>
>
> > Dean,
> >
> > True, static friction is greater than dynamic friction.  However, as
long
> > we're splitting hairs here, define jump.  What I mean is, it is easy to
> > imply that if the pin overcame the static friction it would then make
some
> > large movement, resulting in a large pitch change.  I think arguing that
> it
> > jumps vs. makes micro movements becomes an issue of semantics.  Your
jump
> > can be my micro movement.  What's more, this assumes that friction is
> > constant, whatever the pins position in the hole.  I'm unsure if this
> would
> > be the case or not.
> >
> > Respectfully,
> > William R. Monroe
> >
> > ----- Original Message ----- 
> > From: "Dean May" <deanmay@pianorebuilders.com>
> > To: "'Pianotech'" <pianotech@ptg.org>
> > Sent: Monday, March 28, 2005 8:00 AM
> > Subject: RE: Aha! was flat facts
> >
> >
> > > Static friction is greater than dynamic friction. If a tuning pin
moves
> > > it jumps, it does not turn in micro movements over time.
> > >
> > > Dean
> > > Dean May             cell 812.239.3359
> > > PianoRebuilders.com   812.235.5272
> > > Terre Haute IN  47802
> > >
> > >
> > > > -----Original Message-----
> > > > From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]
On
> > > > Behalf
> > > > Of Ron Nossaman
> > > > Sent: Sunday, March 27, 2005 11:38 AM
> > > > To: Pianotech
> > > > Subject: Re: was flat facts
> > > >
> > > >
> > > >
> > > >> I don't really buy into the "tuning pin turns" theory.
> > > >
> > > > Me either, nor the wire stretching. Music wire doesn't continue to
> > > > stretch over time unless it's tensioned at it's yield point - then
> > > > it stretches, necks down, and breaks.
> > > > Ron N
> > > >
> > > > _______________________________________________
> > > > pianotech list info: https://www.moypiano.com/resources/#archives
> > > >
> > > > -- 
> > > > No virus found in this incoming message.
> > > > Checked by AVG Anti-Virus.
> > > > Version: 7.0.308 / Virus Database: 266.8.3 - Release Date:
03/25/2005
> > > >
> > > >
> > > > -- 
> > > > No virus found in this outgoing message.
> > > > Checked by AVG Anti-Virus.
> > > > Version: 7.0.308 / Virus Database: 266.8.3 - Release Date:
03/25/2005
> > > >
> > > >
> > > > _______________________________________________
> > > > pianotech list info: https://www.moypiano.com/resources/#archives
> > > >
> > > >
> > >
> > > _______________________________________________
> > > pianotech list info: https://www.moypiano.com/resources/#archives
> > >
> > >
> > > _______________________________________________
> > > pianotech list info: https://www.moypiano.com/resources/#archives
> > >
> > >
> >
> >
> > _______________________________________________
> > pianotech list info: https://www.moypiano.com/resources/#archives
> >
> >
>
>
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives
>
>